This invention relates to trailers of the type used to haul particulate material, and more particularly, to a system for automatically cleaning residual material from the floor of a self-unloading trailer.
It has become commonplace to employ what is often referred to as a xe2x80x9cmoving floorxe2x80x9d or xe2x80x9cwalking floorxe2x80x9d load-moving system in the trailers of so-called xe2x80x9cself-unloadingxe2x80x9d trucks used to carry goods like wood chips, sawdust, grains, etc.
Such floors typically comprise a plurality of adjacent slats which lie longitudinally along the length of the trailer floor and which, through a series of repetitive reciprocating sliding movements, carry the load out the rear of the trailer. One example of such a floor is the system described in U.S. Pat. No. 4,143,760. Another example is shown in U.S. Pat. No. 4,492,303.
Although such unloading systems are now commonplace, one inherent problem with them which has not yet been satisfactorily addressed is that such systems leave a good deal of residual material on the floor of the trailer. Such residual material must be manually shovelled or swept out of the trailer by the operator, causing time delays and other inconvenience. This encourages operators to try to clear the trailer of residual material while the load is being unloaded, which is very dangerous.
While there exist load handling systems which comprise movable bulkheads for pushing loads out of a trailer (such systems are shown, for example, in U.S. Pat. Nos. 2,536,476, 3,333,715, 3,050,203, 3,815,764, 5,395,204, 5,009,564 and 5,314,290), these systems are not directed to cleaning residual material out of the bed of a self-unloading trailer, and are not fashioned to meet this objective, as is the present invention.
The present invention is a trailer floor cleaning system for use in a self-unloading trailer having a front, a rear, side walls, and a reciprocating floor conveyor system having a plurality of reciprocable slats. The invention comprises, in one embodiment, a plurality of rails each extending upwardly from the top surface of one of the plurality of slats within the trailer, each rail defined by a plurality of contiguously-aligned fin-like teeth defining, notches between adjacent ones of them.
The invention also comprises a wedge-shaped sweeper mounted on these rails. The sweeper comprises a frame, a covering attached to the frame and enclosing it, a plurality of skate assemblies each attached to a lower portion of the frame and depending downwardly from it, each of the assemblies fashioned to slide along one of the rails, and motive means for moving the sweeper from the front of the trailer towards the rear of the trailer along the rails.
In a further embodiment of the invention, the skate assemblies comprise pivotable pawls and the motive means for moving the sweeper from the front of the trailer towards the rear of the trailer along the rails comprises the pawls acting in ratcheting engagement with the teeth of the rails.
Three rails are used in a preferred embodiment: a central rail extending upwardly from the top surface of a central slat, and two outer rails, each extending upwardly from the top surface of an outer slat near a side wall of the trailer. The outer slats when the floor is in operation reciprocate in unison with one another, but out of unison with the central slat.
To retrofit the system into an existing trailer with a reciprocating floor, the rails can comprise an angle having a flat horizontal portion for attachment to the top surface of a slat and a substantially vertical portion attached to the horizontal portion and extending upwardly therefrom. Such rails can be welded or epoxied to the surfaces of the slats.